Add bin/heat-manage to flake8 checks
Add bin/heat-manage to flake8 checks

Change-Id: I917e5b0aa571f2fced7df6a4818f32ce4b5f1561

miguelgrinberg/heat,pratikmallya/heat,cryptickp/heat,gonzolino/heat,dims/heat,noironetworks/heat,takeshineshiro/heat,srznew/heat,NeCTAR-RC/heat,steveb/heat,pshchelo/heat,steveb/heat,redhat-openstack/heat,ntt-sic/heat,rdo-management/heat,srznew/heat,varunarya10/heat,rh-s/heat,rickerc/heat_audit,NeCTAR-RC/heat,dragorosson/heat,pshchelo/heat,pratikmallya/heat,takeshineshiro/heat,rickerc/heat_audit,jasondunsmore/heat,dragorosson/heat,redhat-openstack/heat,rdo-management/heat,cwolferh/heat-scratch,dims/heat,openstack/heat,noironetworks/heat,gonzolino/heat,rh-s/heat,JioCloud/heat,citrix-openstack-build/heat,maestro-hybrid-cloud/heat,maestro-hybrid-cloud/heat,openstack/heat,cryptickp/heat,varunarya10/heat,ntt-sic/heat,miguelgrinberg/heat,JioCloud/heat,jasondunsmore/heat,cwolferh/heat-scratch,citrix-openstack-build/heat